Temperature control in plasma processing apparatus using pulsed heat transfer fluid flow

A method of controlling a temperature of a chuck in a plasma processing apparatus, the method comprising:

• providing a first heat transfer fluid at a first temperature to the chuck via a first supply line and a first return line coupling the chuck to a first heat transfer fluid reservoir;
• providing a second heat transfer fluid at a second temperature to the chuck via a second supply line and a second return line coupling the chuck to a second heat transfer fluid reservoir;
• controlling a first valve coupling the first heat transfer fluid reservoir with the first supply line and controlling a second valve coupling the second heat transfer fluid reservoir with the second supply line;
• and
• equalizing a level of the first heat transfer fluid reservoir with a level of the second heat transfer fluid reservoir by flowing either the first or second heat transfer fluid through a passive leveling pipe coupling the first heat transfer fluid reservoir to the second heat transfer fluid reservoir.